Multi-hop routing technology in a network composed of a plurality of communication devices (nodes) is intended to ensure a transmission path from a departure point to a destination in order to transmit data. Since a communication problem-causing element, such as jamming, interrupts the communication of nodes within a predetermined range over a network, a transmission path cannot fulfill its role of transferring data normally when the nodes are included in the transmission path.
FIG. 1 is a conceptual diagram illustrating a conventional method of establishing a routing path in a multi-hop network in the event of a communication problem.
In FIG. 1, a routing path 120 that was established before the occurrence of a communication problem is illustrated.
A communication problem area 100 formed by a jammer 110, that is, a communication problem-causing element, is illustrated, and the direction of movement 111 of the jammer 110, that is, a communication problem-causing element, is also illustrated.
As shown in FIG. 1, in a multi-hop network, when a preset routing path experiences a communication problem, it is determined that some nodes included in the routing path experience the communication problem through the exchange of control messages on a routing protocol, and thus a new routing path is established. Here, a node that is experiencing a communication problem is automatically excluded from a routing path because the node does not receive a control message from a neighboring node. That is, a new routing path is established using normal nodes after the passage of a predetermined time in accordance with the operating rules of a predetermined routing protocol, and therefore normal data exchange can be performed between a departure node and a destination node.
However, the damage is not confined to the temporary interruption of data transmission, and the situation becomes more serious because the newly established routing path will not play its role again in a network in which the communication problem-causing element has mobility or there is the mobility of nodes. The reason for this is that a link and nodes that are affected by the communication problem-causing element continuously vary in the mobile environment.
In FIG. 1, the routing path 130 that has been automatically reestablished so that the nodes that are experiencing the communication problem can be avoided is illustrated. As can be seen from FIG. 1, although the routing path 130 is currently set as a path along which communication is possible, it can be easily expected in light of the direction of movement 111 of the jammer 110 that the reestablished routing path 130 will belong to the communication problem area 100 and thus cannot play its role.
The repeated destruction of such routing paths brings about the phenomenon of the interruption of data transmission, thereby resulting in a considerable decrease in the data rate and in great damage to the operation of an application requiring real-time capability.